How to Configure SMBv1 in Windows Registry

This article explains how to locate and modify the specific Windows Registry key responsible for enabling or disabling the Server Message Block version 1 (SMBv1) server component in Windows. Managing this setting directly through the Registry Editor (Regedit) provides a straightforward method for administrators to control legacy protocol configurations and secure their network environments against outdated protocol vulnerabilities.

Registry Path and Value

The SMBv1 server configuration is controlled by a DWORD value located in the LanmanServer parameters path within the registry:

• Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters
• Value Name: SMB1
• Value Type: REG_DWORD

Configuration Values

The SMB1 DWORD value determines whether the SMBv1 server service is active:

• Value Data 0: Disables SMBv1 server functionality.
• Value Data 1: Enables SMBv1 server functionality.

Note: By default in modern versions of Windows, if the SMB1 registry entry does not exist, SMBv1 may already be disabled or removed at the OS component level.

How to Modify the Setting in Regedit

1. Press Windows Key + R, type regedit, and press Enter to launch the Registry Editor.
2. Navigate to the following key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters
3. Look for the SMB1 entry in the right pane:
   • If it exists, double-click SMB1, set the Value data to 0 (to disable) or 1 (to enable), and select Hexadecimal as the base.
   • If it does not exist, right-click an empty space in the right pane, select New > DWORD (32-bit) Value, name it SMB1, and set the desired value data.
4. Click OK to save the changes.
5. Restart the computer or restart the Server service (LanmanServer) for the configuration to take effect.